[3] As a yearling, Nimbus was sent to the sales where he was bought for 5000 guineas by the trainer George Colling, acting on behalf of Henry Glenister.
The colt was trained by Colling at his Hurworth House stable in Newmarket, Suffolk and raced in the colours of Glenister's wife, Marion.
Nimbus made good physical progress over the winter and began his three-year-old season by winning the Classic Trial Stakes at Thirsk.
[6] Aberant built up a clear lead, but Nimbus made rapid progress in the closing stages and caught the favourite on the line to win by a short-head in the closest finish in the race's history.
[7] At Epsom Downs Racecourse a month later, Nimbus started at odds of 7/1 for the Derby in field of thirty-two runners, with Royal Forest, ridden by Gordon Richards being made 9/2 favourite.
Throughout the last half mile he was strongly challenged and briefly headed by Swallow Tail as the two colts went clear of the field.
In the closing stages he was also challenged by the fast-finishing French-trained colt Amour Drake, who moved up along the rails as Nimbus and Swallow Tail drifted towards the centre of the course.